Garnet stands for Generating an Amalgam of Real-time, Novel Editors and Toolkits. It was originally developed by the User Interface Software Group in the Human Computer Interaction Institute in the School of Computer Science at Carnegie Mellon University in the early to mid 1990s. It is an environment for creating interfaces to Common Lisp software.

In 1995, active support for Garnet at CMU was dropped as key people moved on and development focus shifted. The toolkit itself, however, is quite feature complete and stable. It's features include:

Toolkit intrinsics:

A custom object-oriented programming system which uses a prototype-instance model.

A graphics layer that hides the differences between X/11 and Macintosh.

Automatic constraint maintenance: so properties of objects can depend on properties of other objects, and be automatically re-evaluated when the other objects change. The constraints can be arbitrary lisp expressions.